Drive arrangement for a running gear

Abstract

The present invention relates to a drive arrangement for a wheel unit including a wheel unit defining an axial direction and a radial direction, a first torque transmission device and a second torque transmission device. The first torque transmission device is connected in a torsionally rigid manner to the wheel unit and the second torque transmission device is connected in a torsionally rigid manner to the first torque transmission device using a connecting device such that an arrangement substantially coaxial to the axial direction is formed. The wheel unit has a wheel unit end section protruding, along the wheel axis, into a receptacle of the second torque transmission device. A protective unit is arranged between the wheel unit end section and the second torque transmission device, the protective unit being configured to protect the wheel unit end section against damage by the second torque transmission device.

The invention claimed is: 
     
       1. A drive apparatus for a wheel unit of a running gear for a rail vehicle, comprising:
 a wheel unit defining an axial direction and a radial direction; 
 a first torque transmission device; and 
 a second torque transmission device; 
 wherein said first torque transmission device is connected in a torsionally rigid manner to said wheel unit and said second torque transmission device is connected in a torsionally rigid manner to said first torque transmission device using a connecting device, wherein an arrangement substantially coaxial to said axial direction is formed; 
 wherein said wheel unit has a wheel unit end section protruding, along said wheel axis, into a receptacle of said second torque transmission device; 
 wherein a protective unit is arranged between said wheel unit end section and said second torque transmission device; and 
 wherein said protective unit is configured to protect said wheel unit end section against damage by said second torque transmission device in case of failure of said connecting device. 
 
     
     
       2. The drive apparatus according to  claim 1 , wherein, a radial gap is formed between said wheel unit end section and said second torque transmission device;
 wherein said protective unit, in said radial direction, at least partially, fills said radial gap, and 
 wherein said axial direction, at least partially filling said radial gap. 
 
     
     
       3. The drive apparatus according to  claim 2 , wherein, said radial gap, in said axial direction, has a gap length;
 wherein said protective unit, in said axial direction, has a protective unit length; and 
 wherein said protective unit length is 40% to 100%, of said gap length. 
 
     
     
       4. The drive apparatus according to  claim 2 , wherein,
 said radial gap, in said radial direction, has a gap width; 
 wherein said wheel unit end section, in an area of said radial gap, has an end section diameter; and 
 wherein said gap width is 5% to 20% of said end section diameter. 
 
     
     
       5. The drive apparatus according to  claim 2 , wherein
 said protective unit contacts said wheel unit end section via an inner contact surface provided with a transitional fit or contacts said second torque transmission device via an outer contact surface provided with a transitional fit; 
 wherein said radial gap, in said axial direction, has a gap length, 
 wherein said inner contact surface in said axial direction, has an inner contact surface length; 
 wherein said outer contact surface in said axial direction, has an outer contact surface length; and 
 wherein at least one of said inner contact surface length and said outer contact surface length is 30% to 100%, of said radial gap length. 
 
     
     
       6. The drive apparatus according to  claim 1 , wherein,
 said protective unit is made from a plastic material; and 
 wherein said plastic material is one of a rubber material, a polyamide (PA) material, a polyethylene (PE) material, a polyurethane (PUR) material, and a fiber reinforced composite material; and 
 wherein said protective unit being a monolithic component. 
 
     
     
       7. The drive apparatus according to  claim 1 , wherein,
 said wheel unit end section has an axial end surface facing away, in said axial direction, from said wheel unit; 
 wherein said protective unit has a radial collar section covering a part of said axial end surface; and 
 wherein said protective unit is connected to said wheel unit end section via said radial collar section. 
 
     
     
       8. The drive apparatus according to  claim 1 , wherein,
 said first torque transmission device is connected to said second torque transmission device via a threaded connection arrangement between said second torque transmission device and said, wheel unit end section; 
 wherein said threaded connection arrangement has at least one threaded element; 
 wherein said at least one threaded element is arranged in said axial direction and cooperating with said wheel unit end section; and 
 wherein a torsionally rigid connection between said first torque transmission device and said second torque transmission device, is provided via an axial toothing. 
 
     
     
       9. The drive apparatus according to  claim 8 , wherein,
 said at least one threaded element, in said axial direction, has an effective length and, in said radial direction, has a nominal thread diameter; 
 wherein said effective length is 500% to 900% of said nominal thread diameter. 
 
     
     
       10. The drive apparatus according to  claim 8 , wherein
 said at least one threaded element comprises an inner threaded end, and outer threaded end and an unthreaded waisted shank section located between said inner threaded end and said outer threaded end; 
 wherein said at least one threaded element, in said axial direction, has a total threaded element length; 
 wherein at least one of said inner threaded end and said outer threaded end, in said axial direction, has a thread length, said thread length being 10% to 35% of said total threaded element length, said thread length of said outer threaded end, being greater than said thread length of said inner threaded end; and 
 wherein said unthreaded waisted shank section, in said axial direction, has a waisted section length, said waisted section length being 25% to 55% of said total threaded element length. 
 
     
     
       11. The drive apparatus according to  claim 10 , wherein,
 said wheel unit end section has an axial recess; 
 wherein said axial recess extends in said axial direction and being open towards a free end of said wheel unit end section; 
 wherein said axial recess receives a part of a connection arrangement connecting said second torque transmission device to said wheel unit end section; 
 wherein said axial recess receives said part of said connection arrangement with a radial play in said radial direction; 
 wherein an inner end of said part of said connection arrangement is connected to said wheel unit end section in a region of an inner wall, in said axial direction, confining said axial recess at an inner end of said axial recess; 
 wherein said wheel unit end section, in an area of said protective unit, has an end section diameter, and said axial recess, in said axial direction, has an axial recess length, said axial recess length being 80% to 140% of said total threaded element length. 
 
     
     
       12. The drive apparatus according to  claim 8 , wherein,
 said threaded connection arrangement comprises a nut element; 
 wherein said nut element cooperates with an outer threaded end of said threaded element and an abutment of said second torque transmission device; 
 wherein an interface part of said outer threaded end, in said axial direction protrudes beyond said nut element on a side of said nut element facing away from said wheel unit: 
 wherein said interface part, in said axial direction has an interface part length sufficient to connect said threaded element to a tensioning tool for imposing a tensile prestress onto said threaded element; and 
 wherein said second torque transmission device, in particular, forms an outer receptacle receiving said nut element and said interface part of said threaded connection arrangement, said outer receptacle, being closed by a cover element preventing free access to said nut element. 
 
     
     
       13. The drive apparatus according to  claim 1 , wherein,
 said wheel unit end section is formed by a wheel unit shaft of said wheel unit or by a hub of a wheel of said wheel unit. 
 
     
     
       14. A running apparatus, for a rail vehicle, comprising:
 a wheel unit defining an axial direction and a radial direction and a drive unit; 
 wherein said wheel unit is driven by said drive unit via a drive apparatus, wherein the drive apparatus comprises: 
 a first torque transmission device; and 
 a second torque transmission device; 
 wherein said first torque transmission device is connected in a torsionally rigid manner to said wheel unit and said second torque transmission device is connected in a torsionally rigid manner to said first torque transmission device using a connecting device, wherein an arrangement substantially coaxial to said axial direction is formed; 
 wherein said wheel unit has a wheel unit end section protruding, along said wheel axis, into a receptacle of said second torque transmission device; 
 wherein a protective unit is arranged between said wheel unit end section and said second torque transmission device; and 
 wherein said protective unit is configured to protect said wheel unit end section against damage by said second torque transmission device in case of failure of said connecting device. 
 
     
     
       15. A method of assembling a drive apparatus, comprising,
 threading an inner threaded end of a threaded element into a wheel unit end section to bring a first torque transmission device and a second torque transmission device into contact, wherein a protective unit is arranged between said second torque transmission device and said wheel unit end section and an outer threaded end of said threaded element, in an axial direction, protrudes beyond an abutment of said second torque transmission device facing away from said wheel unit end section; 
 screwing a nut element onto said outer threaded end such that an interface part of said outer threaded end, in said axial direction; protrudes beyond said nut element on a side of said nut element facing away from said wheel unit; 
 connecting a tensioning tool to said interface part; imposing, in said axial direction, a defined tensile prestress onto said threaded element via the tensioning tool; 
 advancing said nut element further on said outer threaded end; bringing said nut element into contact with said abutment of said second torque transmission device; and 
 releasing said tensioning tool to press said nut element against said abutment using a tensile force generated by said threaded element, which firmly connects said first torque transmission device and said second torque transmission device.